JPS59140229A - Thermoplastic aromatic polyamide-imide copolymer - Google Patents

Abstract

PURPOSE:The titled copolymer having good moldability and excellent balance among various mechanical properties, comprising three specified structural units at a specified proportion. CONSTITUTION:The titled copolymer comprising a structural unit (A) of formula I (wherein Z is a trifunctional aromatic group in which two of the three functional groups are bonded to adjacent carbon atoms, e.g., a group of formula II), a structural unit (B) of formula III (e.g., formula IV), and a structural unit (C) of formula V (wherein X is -SO2- or a group of formula VI), e.g., a structural unit of formula VII, wherein each of said structural units is present in a proportion such that 1mol of (B+C) is present per mol of A, and B/C is 5-60mol%/ 95-40mol%. This copolymer can show outstandingly excellent balance between heat stability and flow property, and is useful in extrusion or injection molding. In addition, it is also possible to obtain a molding further improved in heat distortion temperature, tensile strength, bending strength, friction/abrasion properties, etc., by subjecting a molding formed by heat molding to a high-temperature treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel thermoplastic aromatic polyamide-imide copolymer that has good moldability, represented by injection moldability, and an excellent balance of mechanical properties.

By polycondensing aromatic tricarboxylic acid anhydride or its derivative with aromatic diamine or its derivative,
It is already well known that aromatic polyamideimides with excellent heat resistance can be obtained.

However, many of the aromatic polyamideimides known so far lack melt moldability, and even if they have melt moldability, they have various drawbacks such as insufficient physical properties. However, they are not always satisfied in terms of practicality.

For example, aromatic polyamideimide produced by a device composed of trimellitic anhydride and 2,6-diamithanthraquinone has excellent heat resistance, but because the polymerization activity of the diamine is low, only a polymer with a low degree of polymerization can be obtained. Moreover, since it is essentially crystalline, it has no melt processability and is far from practical.

Indeed, the general formula imide synthesized from trimellitic anhydride and 4,4'-[sulfonylbis(p-7enyleneoxy)]didiazine (for example, described in JP-A-49-129799) has a flow initiation temperature of The difference in thermal decomposition temperature is 50°C or more, and the thermal stability and fluidity during melt molding are excellent, so it shows good melt moldability, but the flexibility of the diamine component is too high, making molding difficult. The physical properties of the body (especially the flexural modulus) are not necessarily satisfactory.

Although the polyamideimide represented by f,ri4,4'-(furobylbis(p-phenyleneoxy)dianiline) and trimellitic anhydride has excellent thermal stability and fluidity during melt molding, the diamine component is (4
, 4'-sulfonylbis(p-phenyleneoxy)dianiline],
The physical properties of the molded product (particularly the flexural modulus and heat distortion temperature) are insufficient.

Therefore, the present inventors conducted intensive studies with the aim of obtaining an aromatic polyamide-imide having an appropriate degree of polymerization and melt processability, and having an excellent balance of physical properties in molded products. The inventors have discovered that a novel thermoplastic aromatic polyamide-imide copolymer having desired properties can be obtained by combining two components within a specific composition range, and have thus arrived at the present invention.

It is characterized in that the proportion of each structural unit is 1 mol of B10 per 1 mol of A, and 5 to 60 mol% of B10/95 to 40 mol% of S. The present invention provides a thermoplastic aromatic polyamide-imide copolymer.

(However, Z in the above formula is a hexafunctional aromatic OH in which two of the functional groups are bonded to adjacent carbons.

(2) The aromatic group represents a 15O2- group or a 10-group. ) The thermoplastic polyamide-imide copolymer of the present invention is mainly composed of six units represented by A, B and C above.

2 in the above A unit is a functional aromatic group in which two of the six functional groups are bonded to adjacent carbons, and specific examples of the above C unit are as follows.

The ratio of each of the above units in the polyamide-imide copolymer of the present invention is 1 mole of B to 1 mole of A.
A composition ratio range of 5 to 60 mol %/95 to 40 mol, particularly 10 to 40 mol %/90 to 60 mol of cutlet B10 is selected.

If the proportion of B units in the B+C units is 60 molar or more, the degree of polymerization of the resulting copolymer will be low and melt moldability will be significantly reduced, resulting in only molded products with poor mechanical properties.

Furthermore, if the proportion of B units is less than 5 molar fractions of 100 B units, the heat distortion temperature will be relatively low, and only a copolymer with a relatively small elastic modulus will be obtained.

In addition, when the imide bond in the A unit remains in the state of an amic acid bond as its ring-closing precursor, the A' unit is present as a part of the A unit, for example, 50 molar or less, preferably 60 molar or less. It is also within the scope of the present invention.

The polyamide-imide copolymer of the present invention can be produced using any of the many general production methods proposed so far, but among them, the following six methods are representative examples of high practicality. can be mentioned.

(1) Incyanate method: A method in which aromatic diincyanate is reacted with iminodicarboxylic acid synthesized from aromatic tricarboxylic anhydride and/or aromatic tricarboxylic anhydride/aromatic diamine (2/1 molar ratio)
For example, Japanese Patent Publication No. 44-19274, Japanese Patent Publication No. 45-
2397, Special Publication No. 50-66120, etc.)
.

(2) Acid chloride method: A method in which aromatic tricarboxylic acid anhydride chloride and aromatic diamine are reacted (for example, Japanese Patent Publication No. 15637/1984).

(3) Direct polymerization method: A method in which aromatic tricarboxylic acid or its derivatives (excluding acid chloride derivatives) and aromatic diamine are directly reacted in a polar organic solvent in the presence of a dehydration catalyst (for example, Japanese Patent Publication No. 49-4077) .

Among the three methods mentioned above, the acid chloride method is preferred because it is relatively easy to procure raw materials, and because of low-temperature solution polymerization, it is easy to obtain a highly polymerized polyamide-imide with excellent linearity (less branched structure). It has many advantages and is the most recommended manufacturing method. Here, a more specific example of the production of the polyamide-imide copolymer of the present invention by the acid chloride method is as follows. That is, 1 mol of aromatic tricarboxylic acid anhydride monochloride and the following (1)
Mixed diamine 0 consisting of 5 to 60 mol of aromatic diamine of formula and 95 to 40 mol of aromatic diamine of formula (n) below
．． 9 to 1.1 moles are dissolved in an organic polar solvent.

H3 (or -8O□- group or 10- group)H3 Next, this is heated to about 0.5-1
After mixing for an hour, add hydrogen chloride scavenger from 0.9 to 2
．． When about 0 mol is added to accelerate the polymerization reaction rate, the polymerization reaction is completed at around room temperature in a reaction time of 0.5 to 10 hours. The polymer produced at this stage contains most of the A units (for example, 50 to 10
0%) into the ring-closing precursor amide/amic acid unit H 2 , resulting in a so-called polyamide/amic acid. The organic polar solvent used in this first step is N@ such as dimethylacetamide and dimethylformamide.
N-dialkylcarboxylic acid amides, N-methylpyrrolidone, heterocyclic compounds such as tetrahydrothiophene-1,1-dioxide, phenols such as cresol and xylenol, and especially N-methylpyrrolidone and N- N-dimethylacetamide is preferred. Further, the hydrogen chloride scavenger added in the above first step is aliphatic 6th class amines such as trimethylamine, ethylamine, tripropylamine, and tributylamine, and cyclic organic compounds such as pyridine, lutidine, collidine, and quinoline. Base, alkali metal hydroxide, alkali metal carbonate 1. Inorganic bases such as alkali metal acetates, alkali metal oxides, alkaline earth metal hydroxides, alkaline earth metal carbonates, alkaline earth metal acetates, organic oxide compounds such as ethylene oxide, propylene oxide, etc. be.

The polyamideamic acid obtained in the first step is then subjected to a second dehydration ring closure step and converted into the polyamideimide copolymer of the present invention. The dehydration ring closure operation is carried out either by liquid phase ring closure in solution or solid phase hot ring closure by heating in a solid state. There are two types of liquid phase ring closure: a liquid phase chemical ring closure method using a chemical dehydrating agent, and a simple liquid phase thermal ring closure method. The chemical ring closure method uses aliphatic anhydrides such as acetic anhydride, propionic anhydride, halogen compounds such as POOh, 80012, molecular sheep, silica gel, P2O6
, using a chemical dehydrating agent such as A1□03 at a temperature of O~1
It is carried out at 20°C, preferably 10-60C. Also,
In the liquid phase thermal ring closure method, polyamide/amic acid solution is
This is carried out by heating to 00°C, preferably 100 to 250°C. In this case, it is more effective to use an azeotropic solvent useful for removing water, such as benzene, toluene, xylene, or chlorobenzene. Solid phase hot ringing is carried out by first isolating a polyamide/amic acid polymer from the polyamide/amic acid solution obtained in the first step and heat-treating it in a solid state. As a precipitant for isolating the polyamide/amic acid polymer, a liquid such as water, methanol, etc., which is miscible with the reaction mixture solvent but in which the polyamide/amic acid itself is insoluble is employed. The heat treatment is usually performed at 150 to 650°C and 0.5°C.
The conditions for 5 to 50 hours are selected to ensure the desired ring closure rate and melt fluidity.

If the treatment is carried out in the 250 to 650° C. range for too long, the polymer itself tends to form a three-dimensional crosslinked structure, which significantly reduces the fluidity during melting, so care must be taken.

Specific examples of the aromatic diamine represented by the above general formula (1) include the following structural formulas.

H2 is still an aromatic diamine represented by the formula (n) (4,4
'-sulfonylbis(p-phenyleneoxy)dianiline) (3,3'-sulfonylbis(p-phenyleneoxy)
dianiline) (2,2'-sulfonylbis(p-phenyleneoxy)
dianiline) H3 (4,4'-propylbis(p-phenyleneoxy)dianiline).

By the production method detailed above, the polyamide-imide copolymer which is the object of the present invention can be obtained.
To copolymerize copolymerization components other than those constituting the unit, B unit, and C unit in a quantitative range that does not significantly reduce the melt processability and physical properties of the polyamideimide that produces the copolymerization components. is possible and within the scope of the present invention.

The polyamide-imide copolymer of the present invention has a structure in which the imide units are partially ring-opened amic acid bonds, but most have a ring-closed structure, and N,N-dimethylacetamide (hereinafter referred to as DMAC). (abbreviated as !) in a solvent with a polymer concentration of 0.5 parts by weight, and the value of the logarithmic viscosity (η1nh) measured at 30°C is 0.25 or more, preferably 0.6
It is a polymer with a high polymerization degree of 0 or more, and can be used for various purposes such as those listed below.

Compression molding is carried out by tri-blending the polyamide-imide copolymer powder of the present invention with different polymers, additives, fillers, reinforcing agents, etc. as necessary, and then molding the mixture at 300 to 400°C and a pressure of 50°C.
It is carried out under conditions of 0-500 K'i/crl.

In addition, extrusion molding and injection molding are performed by tri-blending the polyamide-imide copolymer of the present invention with different polymers, additives, fillers, reinforcing agents, etc. as necessary, or pelletizing this by extruding it into pellets. is supplied to an extrusion molding machine or an injection molding machine and carried out under a temperature condition of 600 to 400°C. In particular, the aromatic polyamide-imide copolymer of the present invention has an excellent balance of thermal stability and fluidity in the range of 600 to 400°C, and is useful for extrusion molding and injection molding.

In addition, by further subjecting the molded product obtained by heating and melt-molding the polyamide-imide copolymer of the present invention to heat treatment under high-temperature conditions, the molded product has further improved physical properties such as heat distortion temperature, tensile strength, bending strength, and friction and wear characteristics. can be obtained. Such heat treatment conditions include heating the molded product at 260°C or higher and below the glass transition temperature of the molded product, particularly at 240°C.
As described above, it is appropriate to heat the molded product at a temperature below (glass transition temperature -5° C.) for 5 hours or more, particularly 10 hours or more. When the heat treatment temperature exceeds the glass transition temperature of the molded article, the molded article is undesirably deformed during the heat treatment and has a strong tendency to impair its practicality. Although there are no particular restrictions on the equipment for carrying out this heat treatment, an ordinary electrically heated oven can suffice to achieve the purpose.

For film and fiber manufacturing applications, the polymerization termination solution can be applied in dry or wet casting processes;
Furthermore, the isolated polymer can be melt-molded by adding suitable additives as necessary. The laminate is made by impregnating a cloth or mat made of glass fiber, carbon fiber, asbestos fiber, etc. with a copolymer solution, and then pre-curing it by drying/heating to obtain a prepreg.
It is manufactured by pressing under the conditions of 00℃ and 50-300 K9/crl.

For paint applications, after adding and mixing different types of solvents to the polymerization-completed solution as needed, the concentration can be adjusted and the solution can be put to practical use as it is.

Hereinafter, the present invention will be explained in further detail with reference to Examples.

Note that the values of parts and ratios used in the present examples indicate parts by weight, parts by weight, and weight ratios, respectively, unless otherwise specified. Further, the value of the logarithmic viscosity ηinh, which is a measure of the molecular weight of the polymer, was measured in a D M and AC solvent at a polymer concentration of 0.5% and a temperature of 30°C.

Note that measurements of various physical properties were performed according to the following methods.

Bending stress: ASTM D7'90 Bending modulus: Heat deformation temperature: ASTM D648-56 (18
, 56 to 4/crl) Examples 1 to 6 and Comparative Examples 1 to 6 Internal volume 5 equipped with a stirrer, thermometer and nitrogen gas inlet tube
2,6-diamithanthraquinone (hereinafter abbreviated as 2,6-DAQ), 4,
4'-sulfonylbis(p-phenyleneoxy)dianiline (hereinafter abbreviated as P-8ODA) and anhydrous DMA
0 was prepared according to the composition shown in Table 2 to obtain a homogeneous solution. The reaction was cooled to 10°C in an ice/water bath and the 4-(chloroformyl)
253 g (1.20 mol) of phthalic anhydride was heated to a temperature of 10~
The mixture was added in small portions at a rate that maintained the temperature at 30°C.

After further stirring at 20°C for 1 hour, 122g (1
, 2 moles) of anhydrous triethylamine was added in portions at a rate sufficient to maintain the temperature below about 30°C. Next, after stirring for 1 hour, 300 ml of pyridine and 600 ml of acetic anhydride (approximately 6.3 mol) were added, followed by stirring for 30 minutes to complete the reaction.

Next, the polymerized liquid is gradually poured into water under high-speed stirring to precipitate the polymer into particles.Then, the precipitated polymer is crushed into a fine powder using an impact crusher, and then thoroughly washed with water and dehydrated. and then in a hot air dryer at 120°C for 5 hours, followed by 2 hours.
6 with each copolymerization ratio after drying at 00℃ for 6 hours
A seed copolymer dry powder was obtained.

The theoretical structural formulas and molecular formulas of the copolymers obtained in Examples 1 to 6 are as follows. The results of elemental analysis are shown in Table 1, showing good agreement with the theoretical values.

+C9H4N203)+C04H6o2+m(C24H
1604S+.

Next, each of the obtained copolymer powders was compression molded (processing temperature: 66
Two melt moldings were carried out at 0 to 390° C. and a molding pressure of 50 to 100 (7/crA), and the physical properties were measured using the obtained molded test pieces. The results are shown in Table 2.

Margin below - Diamine composition 2.6-DAQ/P-8ODA=10/90.20 as seen from the results of Examples 1 to 3 in Table 2
/80.40/60 molar ratio, ηinh is 0,
An aromatic polyamide-imide copolymer with a high coefficient of 5 or more and excellent mechanical properties was obtained. On the other hand, the diamine composition of Comparative Examples 1 and 2 was 2,6-DAQ/p-8ODA=100/D,
At a molar ratio of 90/10, only an aromatic polyamideimide having poor melt moldability and low mechanical strength was obtained due to low ηinh. In addition, the diamine composition of Comparative Example B is 2.6'-DAQ/P-8ODA = 0/100
The polyamideimide obtained in the molar ratio of Example 1
The thermal deformation temperature was lower than that of Samples 6 to 6, and the bending properties were poor.

Examples 4 to 6 and Comparative Examples 4 to 5 2,6-DAQ and 4,4'-C as diamine components
Five types of aromatic polyamideimide copolymers were prepared by carrying out the same operations as in Example 1 except that 2,2-propylbis(p-phenyleneoxy)]dianiline (hereinafter abbreviated as PODA) was used in the composition shown in Table 4. I got it. This example 4~
The theoretical structural formula and molecular formula of the copolymer obtained in step 6 are as follows, and the results of elemental analysis of this copolymer are shown in Table 3, which agrees well with the theoretical values. It shows.

+C9H4N203 +-+C14H602+'+02
7 H22o2 +t m n Table 6 Elemental analysis results Test pieces were prepared in the same manner as in Example 11 for each of the obtained copolymers, and the physical properties were measured. Table 4 shows the results.

As can be seen from the results of Example 4-B in Table 4, diamine composition 2.6-DAQ/PODA=0-60/100-4
At a molar ratio of 0, an aromatic polyamide-imide copolymer having ηinh of 0.4 or more, having melt moldability and excellent mechanical properties was obtained.

On the other hand, Comparative Example 4 and B diamine composition 2,6-DAQ/
At P'0DA = 90/10 and 0/100 molar ratios, melt moldability was poor, or even if it still had melt moldability, only aromatic polyamideimides with poorly balanced mechanical and thermal properties were obtained. .

Example 7 1.5-DAQ and 6,6'-[ as diamine components
An aromatic polyamide-imide copolymer was obtained by performing the same operations as in Example 1 except for using sulfonylbis(p-phenyleneoxy)]dianiline (hereinafter abbreviated as m-SOD A) in the composition shown in Table 6. . The theoretical structural formula and molecular formula of the copolymer obtained in Example 7 are as follows, and the results of elemental analysis of this copolymer are in good agreement with the theoretical values as shown in Table 5. Ta.

-+C3H4N203++014H1,02++C24
H1604S+t m
However, the properties of the obtained polymer were excellent as shown in Table 6.

Table 5 Elemental analysis results Table 6

Claims (1)

[Claims] Consisting of the following structural units, the ratio of each structural unit is 1 mole of B to 1 mole of A, and 1 mole of B/C is 5 to 60 mole%/95 to 4 mole. A thermoplastic aromatic polyamide-imide copolymer characterized by the following. (However, Z in the above represents a trifunctional aromatic group in which two of the six functional groups are bonded to adjacent carbons, and X represents a 18O2- group or a 10-group.)